Many factors affect the pricing of a ceramic coating, including but not limited to:
The experience, knowledge, and skills of the detailer applying the coating.
The type of coating being applied, all products are different.
The level of preparation needed prior to applying the coating. Some dealerships or detailers will skip steps altogether in order to offer a lower price.
The size, color, and manufacturer of the vehicle can also affect pricing. Some vehicles have much softer clear coats that are harder to prepare for coating application than others.